Two Tiny Particles Having Charges $q _ { 1 } = + 56.0 \mathrm { nC }$

Two tiny particles having charges $q _ { 1 } = + 56.0 \mathrm { nC }$ and $q _ { 2 } = - 46.0 \mathrm { nC }$ are separated by $0.500 \mathrm {~m}$ and held in place, as shown in the figure. A third particle, having a charge of $54.0 \mathrm { nC }$ is placed at the point $A$ , which is $0.18 \mathrm {~m}$ to the left of $q 2$ . How much work is needed to move the third particle from point $A$ to point $B$ , which is $0.40 \mathrm {~m}$ to the left of $q 1$ . All the points in the figure lie on the same line. $\left( k = 1 / 4 \pi \varepsilon _ { 0 } = 9.0 \times 10 ^ { 9 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { C } ^ { 2 } \right)$